package com.atguigu.gulimall.seckill.service.impl;

import com.alibaba.csp.sentinel.Entry;
import com.alibaba.csp.sentinel.SphU;
import com.alibaba.csp.sentinel.annotation.SentinelResource;
import com.alibaba.csp.sentinel.slots.block.BlockException;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.TypeReference;
import com.atguigu.common.to.SeckillOrderTo;
import com.atguigu.common.utils.R;
import com.atguigu.common.vo.MemberRespVo;
import com.atguigu.gulimall.seckill.feign.CouponFeignService;
import com.atguigu.gulimall.seckill.feign.ProductFeignService;
import com.atguigu.gulimall.seckill.interceptor.LoginUserInterceptor;
import com.atguigu.gulimall.seckill.service.SeckillService;
import com.atguigu.gulimall.seckill.to.SeckillSkuRedisTo;
import com.atguigu.gulimall.seckill.vo.SeckillSessionsWithSkus;
import com.atguigu.gulimall.seckill.vo.SkuInfoVo;
import com.baomidou.mybatisplus.core.toolkit.IdWorker;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang.StringUtils;
import org.redisson.api.RSemaphore;
import org.redisson.api.RedissonClient;
import org.springframework.amqp.rabbit.core.RabbitTemplate;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.BoundHashOperations;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.stereotype.Service;

import java.util.*;
import java.util.concurrent.TimeUnit;
import java.util.regex.Pattern;
import java.util.stream.Collectors;

/**
 * @作者：ldk
 * @email 2505496685@qq.com
 * @描述：默认描述
 * @创建时间：12:17 2020-12-19
 * @修改时间：12:17 2020-12-19
 * @修改描述：默认描述
 */
@Slf4j
@Service
public class SeckillServiceImpl implements SeckillService {

    @Autowired
    CouponFeignService couponFeignService;

    @Autowired
    StringRedisTemplate redisTemplate;

    @Autowired
    ProductFeignService productFeignService;

    @Autowired
    RedissonClient redissonClient;

    @Autowired
    RabbitTemplate rabbitTemplate;

    private final String SESSIONS_CACHE_PREFIX="seckill:sessions:";
    private final String SKUKILL_CACHE_PREFIX="seckill:skus:";
    private final String SKU_STOCK_SEMAPHORE="seckill:stock:";//+商品随机码


    @Override
    public void uploadSeckillSkuLatest3Days(){
        //1、去扫描最近三天需要参加秒杀的活动
        R session = couponFeignService.getLates3DaySession();
        if(session.getCode()==0){
            //上架商品
            List<SeckillSessionsWithSkus> sessionData = session.getData(new TypeReference<List<SeckillSessionsWithSkus>>() {
            });
            //缓存到Redis
            //1、缓存活动信息
            saveSessionInfos(sessionData);
            //2、缓存活动的关联商品信息
            saveSessionSkuInfos(sessionData);
        }
    }
    public List<SeckillSkuRedisTo> blockHandler(BlockException e){
        log.error("getCurrentSeckillSkusResource被限流了------------");
        return null;
    }

    //返回当前时间可以参与的秒杀商品信息
    @SentinelResource(value = "getCurrentSeckillSkusResource",blockHandler = "blockHandler")
    @Override
    public List<SeckillSkuRedisTo> getCurrentSeckillSkus() {
        //1、确定当前时间属于哪个秒杀场次
        //1970 -
        long time = System.currentTimeMillis();

        try (Entry entry = SphU.entry("seckillSkus")){
            Set<String> keys = redisTemplate.keys(SESSIONS_CACHE_PREFIX + "*");
            for (String key : keys) {
                String replace = key.replace(SESSIONS_CACHE_PREFIX, "");
                String[] s = replace.split("_");
                long start = Long.parseLong(s[0]);
                long end = Long.parseLong(s[1]);
                if(time>start && time<=end){
                    //2、获取这个秒杀场次需要的所有商品信息
                    List<String> range = redisTemplate.opsForList().range(key, -100, 100);
                    BoundHashOperations<String, String, String> hashOps = redisTemplate.boundHashOps(SKUKILL_CACHE_PREFIX);
                    List<String> list = hashOps.multiGet(range);
                    if(list!=null){
                        List<SeckillSkuRedisTo> collect = list.stream().map(item -> {
                            SeckillSkuRedisTo redisTo = JSON.parseObject((String) item, SeckillSkuRedisTo.class);
                            //                        redisTo.setRandomCode(null); 当前秒杀开始就需要随机码
                            return redisTo;
                        }).collect(Collectors.toList());
                        return collect;
                    }
                    break;
                }
            }
        }catch (BlockException e){

        }
        return null;
    }

    @Override
    public SeckillSkuRedisTo getSkuSeckillInfo(Long skuId) {

        //1、找到所有需要参与秒杀的商品的key
        BoundHashOperations<String, String, String> hashOps = redisTemplate.boundHashOps(SKUKILL_CACHE_PREFIX);

        Set<String> keys = hashOps.keys();
        if(keys != null && keys.size() > 0){
            String regx = "\\d_"+skuId;
            for (String key : keys) {
                if(Pattern.matches(regx,key)){
                    String json = hashOps.get(key);
                    SeckillSkuRedisTo skuRedisTo = JSON.parseObject(json, SeckillSkuRedisTo.class);

                    //随机码
                    long current = System.currentTimeMillis();
                    Long startTime = skuRedisTo.getStartTime();
                    Long endTime = skuRedisTo.getEndTime();
                    if(!(current >= startTime && current <= endTime)){
                        skuRedisTo.setRandomCode(null);
                    }
                    return skuRedisTo;
                }
            }
        }
        return null;
    }

    //TODO 上架秒杀商品的时候，每一个数据都有过期时间
    //TODO 秒杀后续的流程，简化了收货地址等信息。
    @Override
    public String kill(String killId, String key, Integer num) {

        MemberRespVo respVo = LoginUserInterceptor.loginUser.get();

        //1、获取当前秒杀商品的详细信息
        BoundHashOperations<String, String, String> hashOps = redisTemplate.boundHashOps(SKUKILL_CACHE_PREFIX);

        String json = hashOps.get(killId);
        if(StringUtils.isEmpty(json)){
            return null;
        }else{
            SeckillSkuRedisTo redis = JSON.parseObject(json, SeckillSkuRedisTo.class);
            //校验合法性
            Long startTime = redis.getStartTime();
            Long endTime = redis.getEndTime();
            long time = System.currentTimeMillis();


            long ttl = endTime - time;
            //1、校验时间的合法性
            if(time >= startTime && time <= endTime ){
                //2、校验随机码和商品id
                String randomCode = redis.getRandomCode();
                String skuId = redis.getPromotionSessionId() + "_" + redis.getSkuId();
                if(randomCode.equals(key) && killId.equals(skuId)){
                    //3、验证购物数量是否合理
                    if(num <= redis.getSeckillLimit()){
                        //4、验证用户是否已经购买过。幂等性；如果真要秒杀成功，就去占位。
                        String redisKey = respVo.getId()+"_"+skuId;
                        //自动过期
                        Boolean aBoolean = redisTemplate.opsForValue().setIfAbsent(redisKey, num.toString(), ttl, TimeUnit.MILLISECONDS);
                        if(aBoolean){
                            //占位成功声明用户没有购买过
                            RSemaphore semaphore = redissonClient.getSemaphore(SKU_STOCK_SEMAPHORE + randomCode);

                                boolean b = semaphore.tryAcquire(num );
                                if(b){
                                    //秒杀成功；
                                    //快速下单，发送MQ消息 10ms
                                    String timeId = IdWorker.getTimeId();
                                    SeckillOrderTo orderTo = new SeckillOrderTo();
                                    orderTo.setOrderSn(timeId);
                                    orderTo.setMemberId(respVo.getId());
                                    orderTo.setNum(num);
                                    orderTo.setPromotionSessionId(redis.getPromotionSessionId());
                                    orderTo.setSkuId(redis.getSkuId());
                                    orderTo.setSeckillPrice(redis.getSeckillPrice());
                                    rabbitTemplate.convertAndSend("order-event-exchange","order.seckill.order",orderTo);

                                    return timeId;
                                }
                                return null;

                        }else {
                            //占位失败说明用户购买过
                            return null;
                        }
                    }
                }else {
                    return null;
                }
            }else {
                return null;
            }
        }

        return null;
    }

    /**
     * 保存活动信息
     * @param sessionData
     */
    private void saveSessionInfos(List<SeckillSessionsWithSkus> sessionData){
        if(sessionData!=null) {
            sessionData.stream().forEach(session -> {
                long startTime = session.getStartTime().getTime();
                long endTime = session.getEndTime().getTime();
                String key = SESSIONS_CACHE_PREFIX + startTime + "_" + endTime;
                Boolean hasKey = redisTemplate.hasKey(key);
                if (!hasKey) {
                    List<String> collect = session.getRelationSkus().stream()
                            .map(item -> item.getPromotionSessionId().toString() + "_" + item.getSkuId().toString())
                            .collect(Collectors.toList());
                    //缓存活动信息
                    redisTemplate.opsForList().leftPushAll(key, collect);
                }
            });
        }

    }

    private void saveSessionSkuInfos(List<SeckillSessionsWithSkus> sessionData){
        //准备hash操作
        BoundHashOperations<String, Object, Object> ops = redisTemplate.boundHashOps(SKUKILL_CACHE_PREFIX);

        sessionData.stream().forEach(session->{
            session.getRelationSkus().stream().forEach(seckillSkuVo -> {
                //4、随机码？
                String token = UUID.randomUUID().toString().replace("-", "");

                if(!ops.hasKey(seckillSkuVo.getPromotionSessionId().toString()+"_"+seckillSkuVo.getSkuId().toString())){
                    //缓存商品
                    SeckillSkuRedisTo redisTo = new SeckillSkuRedisTo();
                    //1、sku的基本数据
                    R skuInfo = productFeignService.getSkuInfo(seckillSkuVo.getSkuId());
                    if(skuInfo.getCode()==0){
                        SkuInfoVo info = skuInfo.getData("skuInfo", new TypeReference<SkuInfoVo>() {
                        });
                        redisTo.setSkuInfo(info);
                    }

                    //2、sku的秒杀信息
                    BeanUtils.copyProperties(seckillSkuVo,redisTo);

                    //3、设置上当前商品的秒杀时间信息
                    redisTo.setStartTime(session.getStartTime().getTime());
                    redisTo.setEndTime(session.getEndTime().getTime());

                    redisTo.setRandomCode(token);

                    //序列化为json并保存
                    String s = JSON.toJSONString(redisTo);
                    ops.put(seckillSkuVo.getPromotionSessionId().toString()+"_"+seckillSkuVo.getSkuId().toString(), s);

                    //5、使用库存作为分布式的信号量 限流
                    RSemaphore semaphore = redissonClient.getSemaphore(SKU_STOCK_SEMAPHORE + token);
                    //商品可以秒杀的数量作为信号量
                    semaphore.trySetPermits(seckillSkuVo.getSeckillCount());
                }
            });
        });
    }
}
